Shift the decimal nine places
A nanometre is one billionth of a metre. Converting is a single multiplication by ten to the minus ninth, which is the same as moving the decimal point nine places to the left. Reverse it by multiplying metres by 1e9.
Because the numbers get very small, results are usually written in scientific notation: 500 nm is 5 × 10−7 m, not 0.0000005 m spelled out.
Common values, nm to m and neighbouring units
| Nanometres | Metres | Micrometres | Angstroms |
|---|---|---|---|
| 1 nm | 1 × 10−9 | 0.001 µm | 10 Å |
| 10 nm | 1 × 10−8 | 0.01 µm | 100 Å |
| 100 nm | 1 × 10−7 | 0.1 µm | 1,000 Å |
| 500 nm | 5 × 10−7 | 0.5 µm | 5,000 Å |
| 1,000 nm | 1 × 10−6 | 1 µm | 10,000 Å |
| 1,000,000 nm | 0.001 m | 1,000 µm | 10,000,000 Å |
The SI ladder: 1 m = 102 cm = 103 mm = 106 µm = 109 nm = 1010 Å.
Two things people get wrong
- nm is not Nm. Lowercase "nm" is nanometres, a length. Uppercase "Nm" is newton-metres, a torque. They are completely different quantities that happen to share letters.
- Nano is not micro. A micrometre (µm) is 10−6 m; a nanometre is 10−9 m, a thousand times smaller. Bacteria are measured in micrometres, viruses in nanometres.
What sits at the nanometre scale
| Thing | Size |
|---|---|
| Carbon-carbon bond | ~0.15 nm |
| DNA double helix width | ~2 nm |
| EUV lithography wavelength | 13.5 nm |
| Visible light | 380–750 nm |
| HIV virus | ~120 nm |
| Fibre-optic telecom light | 1,310 & 1,550 nm |
Visible light runs roughly 400 nm (violet) to 700 nm (red), a handy anchor for the whole scale.
Common questions
How many nanometres are in a metre?
One metre is 1,000,000,000 nanometres, or ten to the ninth power. A nanometre is one billionth of a metre. To go from metres to nanometres, multiply by 1e9.
How do I convert nanometres to metres?
Multiply the nanometres by ten to the minus ninth, which is the same as dividing by one billion, or shifting the decimal point nine places left. So 500 nm becomes 0.0000005 m, written 5e-7 m.
What is the difference between a nanometre and an angstrom?
One nanometre equals ten angstroms. The angstrom is one ten-billionth of a metre and is still used in crystallography and spectroscopy, though it is not an official SI unit. Nanometres are the SI-preferred choice.
Does 3 nm in a processor mean the transistor is 3 nanometres wide?
No. Since around 2011 the node number is a marketing label, not a physical dimension. No feature on a 3 nm chip actually measures 3 nanometres; the name just signals a newer, denser generation.
